N G Garcia1,2, M A González-Moles2, I Ruiz-Ávila3, M Bravo2, P Ramos-García2, E M Minicucci4, M A C Domingues4, D T Oliveira1. 1. Stomatology Department, Area of Pathology, Bauru School of Dentistry, University of São Paulo, Bauru, São Paulo, Brazil. 2. Oral Medicine Department, School of Dentistry, Instituto de Biomedicina, University of Granada, Granada, Spain. 3. Unidad de Gestión Clínica de Anatomía Patológica, Instituto de Biomedicina de Granada Complejo Hospitalario san Cecilio, Granada, Spain. 4. Pathology Department, Botucatu School of Medicine, State University of São Paulo, Botucatu, São Paulo, Brazil.
Abstract
BACKGROUND: There is inadequate knowledge on the involvement of oncogenic mechanisms linked to the cyclin (CCND1) gene in lip squamous cell carcinoma (LSCC). OBJECTIVE: The aim of this study was to analyse the implication of cyclin D1 in the malignant transformation of lip lesions. METHODS: We immunohistochemically studied 45 actinic cheilitis cases (15 mild dysplasia, 15 moderate dysplasia, 15 severe dysplasia/carcinoma in situ), 30 LSCC cases with adjacent non-tumour epithelium and 15 normal oral epithelium samples for detection of cyclin D1, β-catenin and Ki-67. RESULTS: Cyclin D1 and Ki-67 expressions were significantly increased in the basal layer of premalignant epithelia and peripheral layers of tumour nests vs. CONTROLS: Premalignant epithelia had lost their asymmetrical proliferative pattern. CONCLUSION: Lip carcinogenesis was associated with loss of the asymmetrical proliferative pattern, a preventive mechanism against lip oncogenesis, and with cyclin D1 overexpression.
BACKGROUND: There is inadequate knowledge on the involvement of oncogenic mechanisms linked to the cyclin (CCND1) gene in lip squamous cell carcinoma (LSCC). OBJECTIVE: The aim of this study was to analyse the implication of cyclin D1 in the malignant transformation of lip lesions. METHODS: We immunohistochemically studied 45 actinic cheilitis cases (15 mild dysplasia, 15 moderate dysplasia, 15 severe dysplasia/carcinoma in situ), 30 LSCC cases with adjacent non-tumour epithelium and 15 normal oral epithelium samples for detection of cyclin D1, β-catenin and Ki-67. RESULTS:Cyclin D1 and Ki-67 expressions were significantly increased in the basal layer of premalignant epithelia and peripheral layers of tumour nests vs. CONTROLS: Premalignant epithelia had lost their asymmetrical proliferative pattern. CONCLUSION:Lip carcinogenesis was associated with loss of the asymmetrical proliferative pattern, a preventive mechanism against lip oncogenesis, and with cyclin D1 overexpression.